Bicycle handlebar assembly with v-shaped stem

ABSTRACT

A bicycle handlebar assembly comprises a base bar, a v-shaped stem selectively removable from the base bar, and a bicycle fork assembly. Control cables from the bicycle may be routed from the base bar into hollow diverging stem members of the v-shaped stem. The bicycle fork assembly comprises an external-steerer fork having a load-bearing member and a preload tensioning rod. The preload tensioning rod fits within a head tube of the bicycle, and a hollow space around the preload tensioning rod accommodates control cables passing from the v-shaped stem into a hollow portion of the bicycle frame. The v-shaped stem is secured against the base bar by a pair of nut plates. In some examples, an engagement portion of an accessory such as an aerobar extension assembly is configured to secure the v-shaped stem and an aerobar extension against the base bar.

FIELD

This disclosure relates to bicycles. More specifically, the disclosedembodiments relate to bicycle handlebar assemblies.

INTRODUCTION

The handlebar assembly of a bicycle may affect many bicycle performancecharacteristics. For example, the stem, handlebars, and fork assembly ofa bicycle may affect aerodynamic performance, stiffness, and/or handlingprecision. Handlebar assembly design may also affect the routing ofbicycle control cables (e.g., shifter cables and brake cables) and theattachment of accessories to the front end of the bicycle. There is aneed for a handlebar assembly that is an improvement in these areas overexisting systems.

SUMMARY

The present disclosure provides systems, apparatuses, and methodsrelating to bicycle handlebar assemblies. In some embodiments, a bicyclehandlebar assembly according to aspects of the present teachingscomprises a base bar and a v-shaped stem selectively attachable to thebase bar, including a pair of stem members diverging from a junctionportion; each stem member having an aperture near a distal endconfigured to receive one or more control cables from a bottom surfaceof the base bar into a hollow interior of the corresponding stem member;and the junction portion of the stem having an aperture for routing thecontrol cables from the stem members into a head tube portion of abicycle frame.

In some embodiments, a bicycle handlebar assembly according to aspectsof the present teachings comprises a base bar including means forrouting bicycle control cables from shifter assemblies of the bicycledisposed at lateral edge portions of the base bar to a pair of spacedapart locations symmetrically disposed along a bottom surface of thebase bar; and a stem including a pair of diverging stem membersextending from a junction portion in a v-shaped configuration; whereinthe stem is selectively attachable to the base bar, wherein each stemmember has an aperture at its distal end which is configured to receiveat least one of the control cables from a complementary one of thespaced apart locations into a hollow interior of the stem member, andwherein the junction portion of the stem has an aperture for routing thecontrol cables from the stem members into a head tube portion of abicycle frame.

In some embodiments, a bicycle handlebar assembly according to aspectsof the present teachings comprises a base bar including groovessymmetrically disposed along a bottom surface of the base bar, eachgroove shaped to accommodate control cables of a bicycle, and eachgroove extending to a depression formed in the bottom surface of thebase bar; a stem, selectively removable from the base bar, including apair of diverging stem members extending from a junction portion in av-shaped configuration, each stem member including a distal endconfigured to mate and align with one of the depressions formed in thebottom surface of the base bar, and the distal end of each stem memberfurther including an aperture configured to receive control cables fromone of the grooves of the base bar into a hollow interior portion of thecorresponding stem member; and a pair of nut plate receiving aperturessymmetrically disposed along a top surface of the base bar and eachconfigured to receive either a retaining nut plate for securing one ofthe stem members to the base bar, or an attachment portion of an aerobarextension configured to secure the aerobar extension to the top surfaceof the base bar while also securing one of the stem members to the basebar.

In some embodiments, a bicycle handlebar assembly according to aspectsof the present teachings comprises a base bar; a stem, selectivelyremovable from the base bar, including a pair of hollow diverging stemmembers extending from a junction portion in a v-shaped configuration;means for routing control cables of a bicycle from the base bar and intothe stem; and means for securing the stem to a bottom surface of thebase bar; and means for selectively securing aerobar extensions to a topsurface of the base bar.

Features, functions, and advantages of the present teachings may beachieved independently in various embodiments of the present disclosure,or may be combined in yet other embodiments, further details of whichcan be seen with reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an illustrative bicycle in accordancewith aspects of the present disclosure.

FIG. 2 is a top view of an illustrative base bar and v-shaped stem inaccordance with aspects of the present disclosure.

FIG. 3 is a semi-transparent isometric view of the base bar and v-shapedstem of FIG. 2 , showing a pair of illustrative nut plates attaching thev-shaped stem to the bottom surface of the base bar.

FIG. 4 is an isometric view of one of the nut plates of FIG. 3 .

FIG. 5 is another isometric view of one of the nut plates of FIG. 3 .

FIG. 6 is a bottom view of the base bar of FIGS. 2-3 , shown without thev-shaped stem or nut plates.

FIG. 7 is a bottom view of the base bar of FIGS. 2-3 with the v-shapedstem attached.

FIG. 8 is a top view of the v-shaped stem of FIGS. 2-3 .

FIG. 9 is a bottom isometric view of a base bar and v-shaped stemattached to a bicycle frame and control assemblies, showing controlcables of the bicycle routed along illustrative grooves in the base barin accordance with aspects of the present disclosure.

FIG. 10 is a semi-transparent top isometric view showing an illustrativerouting of bicycle control cables from control assemblies, through abase bar and v-shaped stem, and into a bicycle frame, in accordance withaspects of the present disclosure.

FIG. 11 is an isometric view of an illustrative fork assembly inaccordance with aspects of the present disclosure.

FIG. 12 is an isometric view of the fork assembly of FIG. 11 fittedpartially within an illustrative bicycle frame portion and attached to av-shaped stem, in accordance with aspects of the present disclosure.

FIG. 13 is an isometric view showing a greater portion of the bicycleframe of FIG. 12 .

FIG. 14 is an isometric view depicting an illustrative preload insert,in accordance with aspects of the present disclosure.

FIG. 15 is an isometric view showing the preload insert of FIG. 14disposed on an illustrative bicycle bearing race.

FIG. 16 is a top view of the fork assembly of FIG. 11 , showing anillustrative fork top.

FIG. 17 is an isometric view of an exemplary base bar and v-shaped stemattached to a bicycle frame, showing illustrative spacers in accordancewith aspects of the present disclosure.

FIG. 18 is an isometric view of an exemplary base bar and v-shaped stemwith an illustrative aerobar extension assembly securing the v-shapedstem to the base bar, in accordance with aspects of the presentdisclosure.

FIG. 19 is a top isometric view of an illustrative engagement portion ofthe aerobar extension assembly of FIG. 16 .

FIG. 20 is a bottom isometric view of the engagement portion of FIG. 17.

DETAILED DESCRIPTION

Various aspects and examples of a bicycle handlebar assembly including av-shaped stem are described below and illustrated in the associateddrawings. Unless otherwise specified, a handlebar assembly in accordancewith the present teachings, and/or its various components may, but arenot required to, contain at least one of the structures, components,functionalities, and/or variations described, illustrated, and/orincorporated herein. Furthermore, unless specifically excluded, theprocess steps, structures, components, functionalities, and/orvariations described, illustrated, and/or incorporated herein inconnection with the present teachings may be included in other similardevices and methods, including being interchangeable between disclosedembodiments. The following description of various examples is merelyillustrative in nature and is in no way intended to limit thedisclosure, its application, or uses. Additionally, the advantagesprovided by the examples and embodiments described below areillustrative in nature and not all examples and embodiments provide thesame advantages or the same degree of advantages.

This Detailed Description includes the following sections, which followimmediately below: (1) Definitions; (2) Overview; (3) Examples,Components, and Alternatives; (4) Illustrative Combinations andAdditional Examples; (5) Advantages, Features, and Benefits; and (6)Conclusion. The Examples, Components, and Alternatives section isfurther divided into subsections A through F, each of which is labeledaccordingly.

Definitions

The following definitions apply herein, unless otherwise indicated.

“Substantially” means to be more-or-less conforming to the particulardimension, range, shape, concept, or other aspect modified by the term,such that a feature or component need not conform exactly. For example,a “substantially cylindrical” object means that the object resembles acylinder, but may have one or more deviations from a true cylinder.

“Comprising,” “including,” and “having” (and conjugations thereof) areused interchangeably to mean including but not necessarily limited to,and are open-ended terms not intended to exclude additional, unrecitedelements or method steps.

Terms such as “first”, “second”, and “third” are used to distinguish oridentify various members of a group, or the like, and are not intendedto show serial or numerical limitation.

“Coupled” means connected, either permanently or releasably (unlessotherwise specified), whether directly or indirectly through interveningcomponents

Overview

In general, a bicycle handlebar assembly in accordance with the presentteachings includes a base bar and a v-shaped stem selectively attachableto the base bar. The base bar, also called a handlebar, or in some casesa drop bar, supports bicycle control assemblies (e.g., shifters, brakelevers, and/or the like). The v-shaped stem, in accordance with thepresent teachings, has two stem members diverging from a junctionportion in a “v” or “v-shaped” configuration. A top surface of the basebar includes a pair of nut plate apertures, and the nut plate aperturesare each configured to receive either a retaining nut plate for securingone of the stem members to the base bar, or an attachment portion of abicycle accessory configured to secure the accessory to the base barwhile also securing one of the stem members to the base bar. In someexamples, the bicycle accessory comprises an aerodynamic handlebarextension, which may be referred to as an aerobar extension.Alternatively, or additionally, the bicycle accessory may comprise oneor more lamps, reflectors, bicycle computers, mounts, bells, horns,and/or any other suitable device.

Each stem member has, near a respective end distal the junction portion,an aperture configured to receive bicycle control cables from the basebar. The cables may be routed from the base bar via the stem-memberapertures into the v-shaped stem, and from the junction portion of thev-shaped stem into a head tube or other portion of the bicycle frame.

The bicycle handlebar assembly, in accordance with the presentteachings, further may include a fork assembly. Typically, the forkassembly comprises an external steerer fork assembly, also called abayonet-style fork assembly, configured to fit partially within a headtube portion of a bicycle frame. The fork assembly includes aload-bearing member disposed at a front surface of the fork assembly, apre-load tensioning rod disposed along an axis of rotation of the forkassembly, a hollow portion disposed around the tensioning rod, and a topaperture configured to receive control cables from the v-shaped stem.The tensioning rod and associated hollow portion fit within the headtube portion of the bicycle frame, and the hollow portion accommodatesthe cables as they pass through the head tube portion. The cables may berouted along interior and/or exterior portions of the bicycle frameand/or fork blades to front and rear derailleurs, brakes, and/or othersuitable bicycle components.

Examples, Components, and Alternatives

The following sections describe selected aspects of exemplary handlebarassemblies, as well as related systems and/or methods. The examples inthese sections are intended for illustration and should not beinterpreted as limiting the entire scope of the present disclosure. Eachsection may include one or more distinct embodiments or examples, and/orcontextual or related information, function, and/or structure.

A. Illustrative Bicycle

FIG. 1 depicts an illustrative bicycle 30, according to aspects of thepresent teachings. Bicycle 30 includes a bicycle frame 32 configured tosupport a seat assembly 34, a gear assembly (or drive train assembly)36, wheel assemblies 38, handlebar assembly 40, and/or any othersuitable bicycle systems. Bicycle frame 32 typically includes one ormore hollow tubes comprising a metal material, an alloy material, acomposite material, and/or other suitable material. For example, bicycleframe 32 may comprise steel, aluminum, carbon fiber, titanium, and/orthe like. Gear assembly 36 may include one or more derailleur gearsystems (e.g., including front chain rings, a rear cassette, and frontand rear derailleurs), hub gear systems, single-speed gear systems,and/or the like.

In the example depicted in FIG. 1 , bicycle 30 comprises a road bicycle.Alternatively, or additionally, bicycle 30 may comprise characteristicsand/or systems suitable for touring bicycles, randonneur bicycles,hybrid bicycles, cyclocross bicycles, mountain bicycles, time trialbicycles, triathlon bicycles, BMX bicycles, cruiser bicycles, electricbicycles, motorized bicycles, and/or any other suitable type of bicycle.

B. Illustrative Handlebar Assembly

As shown in FIGS. 2-10 , this section describes illustrative handlebarassembly 40 in more detail. Handlebar assembly 40 is an example of ahandlebar assembly according to aspects of the present teachings.

FIG. 2 is a top view of an illustrative base bar 45 and v-shaped stem 50of handlebar assembly 40. Base bar 45 is an elongate bar configured tosupport one or both hands of a person riding bicycle 30, and typicallyalso to support control assemblies such as brake/shifter assemblies. Insome examples, base bar 45 has curved bend portions 47 extending fromlateral edge portions 49 of the base bar, in which case base bar 45 maybe referred to as a drop bar or drop-style handlebar.

V-shaped stem 50 includes a pair of stem members 52 diverging from ajunction portion 54. V-shaped stem 50 is selectively attachable to basebar 45. Typically, v-shaped stem 50 attaches to base bar 45 at oradjacent distal ends 56 of stem members 52, at a distal end of the stemrelative to junction portion 54. Means for attaching v-shaped stem 50 tobase bar 45 may include at least two nut plate apertures 60 disposedalong a top portion 65 of the base bar. In the example depicted in FIG.2 , nut plate apertures 60 are disposed symmetrically along top portion65 of base bar 45 (e.g., the nut plate apertures are disposedsymmetrically about a base bar center point 66 located at a midpointbetween lateral edge portions 49). Alternatively, nut plate apertures 60may be disposed asymmetrically about center point 66.

In the example depicted in FIG. 2 , a nut plate aperture 60 is disposedat each of two locations on either side of lateral center point 66 ofbase bar 45. In other examples, two or more nut plate apertures 60 maybe disposed at each location. In some examples, unequal numbers of nutplate apertures 60 may be disposed at each location. The number of nutplate apertures may be selected based on a desired security of theconnection between v-shaped stem 50 and base bar 45, a desired stress orload applied to the v-shaped stem, a desired weight for a retainingdevice received in the nut plate apertures, and/or other suitablefactors.

In some examples, base bar 45 has one or more hollow interior portionsunderneath nut plate apertures 60, and the nut plate apertures allowaccess to the hollow interior portions. Alternatively, or additionally,base bar 45 may be solid in the vicinity of nut plate apertures 60, andthe nut plate apertures may define bores extending from top portion 65through the base bar.

Nut plate apertures 60 are configured to receive respective nut plates70 (see, e.g., FIGS. 3-5 ) for fastening v-shaped stem 50 to base bar45. FIG. 3 depicts illustrative nut plates 70 received in respective nutplate apertures 60; FIGS. 4-5 are isometric views of an illustrative nutplate 70. Nut plate 70 typically includes at least one nut plateprojection 72 protruding from a nut plate base 74. Nut plate projections72 are each configured to fit within a complementary opening formed inone of the nut plate apertures 60. In the example shown in FIGS. 4-5 ,nut plate projections 72 include bores 75 each configured to receive afastener. In some cases, bores 75 may be internally threaded. Bores 75may extend through nut plates 70, such that the bores are accessiblefrom above base bar 45, or may terminate below the nut plates (e.g.,within nut plate projections 72), such that the bores are not accessiblefrom above the base bar.

Typically, nut plates 70 secure v-shaped stem 50 to base bar 45 byretaining the v-shaped stem against an underside of the base bar, e.g.with bolts or other fasteners passing through apertures in the distalends 56 of the stem and into projections 72 of the nut plates, therebycompressing the base bar between distal ends 56 and the nut plates.

FIG. 6 is a bottom view of base bar 45 illustrating two spaced-apartlocations, generally indicated at 80, symmetrically disposed along abottom surface 82 of the base bar. Spaced-apart locations 80 aretypically disposed symmetrically about center point 66 of the base bar.A distance between spaced-apart locations 80 is typically substantiallyequal to a distance between distal ends 56 of stem members 52.

In general, spaced-apart locations 80 are configured to facilitateattachment of stem members 52 to base bar 45. In the example shown inFIG. 6 , spaced-apart locations 80 each include a depression 83 inbottom surface 82 of base bar 45. Distal ends 56 of stem members 52 areconfigured to mate and align with depressions 83. The mating of distalends 56 to depressions 83 helps to secure v-shaped stem 50 against basebar 45 (e.g., by tending to prevent rotation of the v-shaped stemrelative to the base bar) and helps to ensure that the v-shaped stem andthe base bar are properly aligned during attachment. In some cases,bottom surface 82 of base bar 45 may include relief portions rather thandepressions to facilitate the alignment and attachment of v-shaped stem50 with the base bar.

FIG. 7 is a bottom view of base bar 45 with v-shaped stem 50 attached,and FIG. 8 is a top view of v-shaped stem 50 depicting distal ends 56,which typically engage bottom surface 82 of base bar 45 when thev-shaped stem is attached to the base bar. Spaced-apart locations 80each include means for one of the nut plates 70 to engage v-shaped stem50 (e.g., to engage distal end 56 of one of the stem members 52).

In some examples, spaced-apart locations 80 include one or morebottom-surface apertures 84 in bottom surface 82. In the exampledepicted in FIGS. 6-8 , bottom-surface apertures 84 in bottom surface 82are aligned with nut-plate apertures 60 in top portion 65, such thatnut-plate projections 72 pass through apertures 60 and into passagesdefined between nut-plate apertures 60 in top portion 65 andbottom-surface apertures 84 in bottom surface 82. Portions of nut-plateprojections 72 distal nut-plate base 74 extend within the passagestoward bottom-surface apertures 84 (e.g., substantially tobottom-surface apertures 84, and/or slightly above or belowbottom-surface apertures 84).

Fasteners 90, such as bolts, retain v-shaped stem 50 against bottomsurface 82 by passing through fastener apertures 92 within distal ends56 and into bores 75 of nut-plate projections 72. Nut-plate bases 74engage with top portion 65 of base bar 45 to retain nut-plateprojections 72 within the passages defined between nut-plate apertures60 and bottom-surface apertures 84. Nut-plate bases 74 also provide asmooth surface adjacent top portion 65 of the base bar for increasedaesthetic appeal. For example, top portions of nut-plate bases 74 may beconfigured to be flush with adjacent portions of top portion 65, and/ormay have a color and/or finish similar to a color and/or finish of thetop portion.

In the example depicted in FIGS. 6-7 , bottom surface 82 of base bar 45has grooves 100 symmetrically disposed about center point 66 extendingtoward spaced-apart locations 80. Typically, at least one groove 100extends from each lateral edge portion 49 of the base bar to one of thedepressions 83. In the example shown in FIGS. 6-7 , one groove extendsfrom each lateral edge portion 49 to the nearest depression 83.Alternatively, or additionally, more than one groove 100 may extend fromeither or both lateral edge portions 49. In some examples, grooves 100extend from one lateral edge portion 49 to the other lateral edgeportion, forming one or more continuous grooves extending across bottomsurface 82. In other examples, grooves may not be present.

As shown in FIG. 7 , junction portion 54 of v-shaped stem 50 has ajunction-portion aperture 102 in a lower surface 103 of the junctionportion. Junction-portion aperture 102 allows access to a hollowinterior portion 104 of v-shaped stem 50. Hollow interior portion 104may include one or more hollow spaces, chambers, and/or channelsdefining a passage between junction-portion aperture 102 and distal ends56 of stem members 52. In some examples, hollow interior portion 104includes cable guide tubes extending from distal ends 56 tojunction-portion aperture 102, and some or all of the interior ofv-shaped stem 50 outside of the guide tubes may be solid or obstructedby other internal structure.

FIG. 8 is a top view of v-shaped stem 50 illustrating distal-endapertures 105 disposed at distal ends 56 of stem members 52 of thev-shaped stem. Distal-end apertures 105 are in fluid communication withjunction-portion aperture 102 via hollow interior portion 104 ofv-shaped stem 50. When v-shaped stem 50 is secured against base bar 45by nut plates 70, as described above, grooves 100 of base bar 45 allowaccess from bottom surface 82 of the base bar to the interior ofv-shaped stem 50 via distal-end apertures 105.

As shown in FIG. 9 , which is a bottom isometric view, control cables115 are connected to shifter assemblies 120 disposed on base bar 45 ator near respective lateral edge portions 49. Shifter assemblies 120 mayinclude any suitable actuators for bicycle control systems, includinggear shifters, brakes, and/or the like. Cables 115 couple shifterassemblies 120 to the associated bicycle control system (e.g., a gearingsystem or a brake). In some cases, cables 115 may include wires encasedin a housing. In other cases, cables 115 may be a hydraulic line. Instill other cases, cables 115 may be configured to transmit electronicsignals.

In the example shown in FIG. 9 , cables 115 are routed along bottomsurface 82 of base bar 45 via grooves 100. Routing cables 115 withingrooves 100 helps to protect the cables from damage and from pressure,strain, and/or stress that may interfere with their function. Distal-endapertures 105 are each configured to receive bicycle control cables 115from one of the grooves 100 into hollow interior portion 104 of v-shapedstem 50.

Alternatively, or additionally, base bar 45 may have one or more hollowinterior portions, and cables 115 may be routed from shifter assemblies120 to distal-end apertures 105 via hollow interior portions of the basebar. Apertures may be provided in surfaces of base bar 45 to allowcables 115 to enter the base bar (e.g., near shifter assemblies 120) andto exit the base bar (e.g., into distal-end apertures 105).

FIG. 10 is a semi-transparent view depicting cables 115 routed fromshifter assemblies 120, along grooves 100 (in bottom surface 82 of basebar 45, see FIG. 9 ), through distal-end apertures 105 andjunction-portion aperture 102, and into head tube portion 150 of bicycleframe 32. Head tube portion 150 is discussed in conjunction with forkassembly 200 below.

C. Illustrative Fork Assembly

This section describes an illustrative fork assembly 200, as shown inFIGS. 11-16 , according to aspects of the present teachings.

As shown in FIG. 11 , fork assembly 200 includes a fork top, generallyindicated at 205, which is rigidly connectable to junction portion 54 ofv-shaped stem 50. Typically, fork top 205 is configured to mate andalign with junction portion 54. For example, fork top 205 may includerecesses and/or projections (e.g., disposed on an upper surface 207)configured to mate with complementary recesses and/or projections ofjunction portion 54. Additionally, or alternatively, one or morefasteners may secure junction portion 54 to fork top 205 and/or to othercomponents of fork assembly 200 and/or bicycle frame 32. Fork top 205includes at least one top aperture 210 configured to receive cables 115from v-shaped stem 50. Top aperture 210 is substantially aligned withjunction-portion aperture 102 to facilitate passage of bicycle controlcables through the apertures. Alternatively, or additionally, a preloadinsert may be positioned within top aperture 210 (see FIGS. 14-15 andassociated description below).

Fork assembly 200 further includes a load-bearing member 215 (alsocalled a load-bearing portion and/or a front load-bearing portion)disposed at a front portion of the fork assembly (e.g., at a fork frontsurface 218). Load-bearing member 215 extends between fork top 205 andone or more fork blades 220. One or more of fork blades 220 may beintegral with load-bearing member 215. Load-bearing member 215 bearsloads caused by, e.g. the weight of base bar 45 and/or pressure appliedto the base bar by a rider of bicycle 30. Load-bearing member 215 alsofunctions to steer the bicycle, by transmitting torque applied to thebase bar by a rider to the fork blades, and thus to the front wheel ofthe bicycle. In this manner, load-bearing member 215 acts as an externalsteerer, and replaces the steering function of a more traditionalsteerer tube, which would be positioned inside a head tube of thebicycle.

Load-bearing member 215 and/or fork blades 220 may have hollowinteriors. Hollow interiors of load-bearing member 215 and/or forkblades 220 may reduce the weight of bicycle 30 compared to a bicyclehaving a solid load-bearing member and/or solid fork blades, and/or mayallow passage of cables 115. One or more of fork blades 220 may includeat least one fork-blade aperture 222 configured to allow cables 115 toexit the fork blade and connect to a control assembly adjacent a frontwheel of the bicycle, for example to control a disc brake.

Fork assembly 200 further includes a tensioning rod 230 (also called apreload rod, preload tensioning rod, and/or central tensioning rod)disposed behind load-bearing member 215. In the example depicted in FIG.11 , tensioning rod 230 extends substantially along an axis of rotation235 of fork assembly 200, but in other examples, the tensioning rod maybe offset from the axis of rotation, and/or may not be parallel to theaxis of rotation. A hollow portion or space 240 adjacent tensioning rod230 is configured to accommodate passage of cables 115. Tensioning rod230 extends from a lower surface 242 of fork assembly 200 through space240 toward fork top 205.

As shown in FIG. 12 , tensioning rod 230 and space 240 fit within headtube portion 150 of bicycle frame 32. Head tube portion 150 is sizedsuch that space 240 within the head tube portion has sufficient volumeto allow passage of cables 115. Typically, the volume within head tubeportion 150 is sufficiently large that cables 115 may pass throughfreely, such that the functioning of the cables is not impeded by, e.g.,pressure or tension from the head tube portion and/or from tensioningrod 230.

From head tube portion 150, some or all of cables 115 may pass intohollow interior portion 244 of bicycle frame 32. For example, asillustrated in FIG. 13 , an aperture 245 in head tube portion 150 may beconfigured to receive at least a subset of cables 115 into hollowinterior portion 244. Alternatively, or additionally, the hollowinterior of head tube portion 150 may be substantially contiguous withhollow interior portion 244.

FIG. 14 is an isometric view of an illustrative preload insert 246,which may be used in conjunction with fork top 205. Preload insert 246is configured to preload headset bearings facilitating rotation of forkassembly 200 relative to head tube portion 150. Preload insert 246 ispositioned on an upper end of tensioning rod 230. Typically, preloadinsert 246 has a bore 247 configured to receive an end portion oftensioning rod 230, such that the preload insert is positioned on top ofthe rod within fork top 205. An upper portion 248 of preload insert 246includes apertures 250 configured to allow cables 115 to pass into headtube portion 150. Interchangeable preload inserts 246 having differenttypes, sizes, shapes, and/or numbers of apertures 250 may be selectivelymounted within fork top 205 to facilitate different cable routingconfigurations.

Preload insert 246 further includes a steering stop 249. Steering stop249 projects from a side of preload insert 246 and is configured tolimit the angular span over which the preload insert can rotate withinhead tube portion 150. For example, steering stop 249 may be sized andshaped such that the steering stop engages internal walls of head tubeportion 150 when rotated to a predetermined position. Because base bar45 and steering stop 249 rotate together, steering stop 249 preventshandlebar assembly 40 and fork assembly 200 from rotating far enough tocontact frame 32, which could damage the bicycle. By preventingover-rotation of handlebar assembly 40 and fork assembly 200, steeringstop 249 may also prevent cables 115 from being strained.

FIG. 15 is an isometric view showing preload insert 246 positioned atthe top of head tube portion 150. Upper portion 248 of preload insert246 is disposed on an upper bearing race 251 and configured to apply apreload to the race. The preload may help to prevent upper bearing race251 from skidding when fork assembly 200 rotates relative to bicycleframe 32 (e.g., when the bicycle is steered).

Preload insert 246 is typically secured within fork top 205 by screws,mating surfaces, clips, clamps, and/or any other suitable mechanism. Insome examples, preload insert 246 is disposed within fork top aperture210, and fork top 205 is configured such that the aperture may betightened around the preload insert. In other words, fork top 205 may beconfigured to act as a pinch clamp.

FIG. 16 is a top view of fork top 205 depicting illustrative preloadinsert 246 positioned within the fork top. In the embodiment depicted inFIG. 16 , preload insert 246 includes three apertures 250 configured toreceive cables 115 into space 240 within head tube portion 150. Fork top205 includes a front top aperture 252 configured to receive one or moreof cables 115 into a channel and/or hollow interior portion ofload-bearing member 215. Cables 115 passing into load-bearing member 215via front top aperture 252 may be routed through the load-bearing memberinto one or more fork blades 220, and may exit the fork blade throughfork-blade aperture 222. Having exited fork blades 220 throughfork-blade aperture 222, cables 115 may connect to a bicycle controlsystem adjacent a front wheel of the bicycle, such as a disc brake.

The embodiment depicted in FIG. 16 may, for example, allow a cable forcontrolling a front brake of the bicycle to be routed through front topaperture 252, and three other cables to each be routed into head tubeportion 150 through a respective one of the three exemplary preloadinsert apertures 250. In some examples, the three other cables include arear brake cable, a rear derailleur cable, and a front derailleur cable.However, the example of FIG. 16 may be used in conjunction with adifferent number or different type of cables 115.

Fork assembly 200 is configured to rotate about head tube portion 150,e.g., in response to rotation of base bar 45. For example, a rider ofbicycle 30 may rotate base bar 45 while turning the bicycle.Load-bearing member 215 and tensioning rod 230 rotate together aboutaxis of rotation 235 (see FIG. 12 ). Tensioning rod 230 rotates withinhead tube portion 150, and load-bearing member 215 rotates external toany tubes of bicycle 30. As shown in FIGS. 12-13 , a front surface 260of head tube portion 150 has a shape complementary to a shape of a rearsurface 255 of load-bearing member 215, so that the load-bearing membermoves easily about the head tube portion when fork assembly 200 isrotated.

Fork assembly 200 may include any suitable headset components configuredto facilitate rotation of the fork assembly relative to head tubeportion 150. For example, fork assembly 200 may include bearingsdisposed between head tube portion 150 and lower surface 242, and/orbetween the head tube portion and fork top 205. Bearing race 251,depicted in FIG. 15 , is an example of a headset component.

D. Illustrative Spacers

This section describes illustrative stem spacers 270 and base barspacers 280, as shown in FIG. 17 .

FIG. 17 depicts stem spacers 270 disposed between junction portion 54 ofv-shaped stem 50 and fork top 205. Typically, stem spacers 270 areconfigured to be removably disposed between lower surface 103 ofjunction portion 54 (see FIG. 7 ) and upper surface 207 of fork top 205(see FIG. 11 ). Stem spacers 270 may be configured to mate and alignwith upper surface 207 and/or lower surface 103. In some examples,recesses and/or projections disposed on stem spacers 270 are configuredto mate with complementary recesses and/or projections disposed on uppersurface 207 and/or lower surface 103. Recesses and/or projections onupper surface 207 and lower surface 103 may be configured to mate witheach other in the absence of stem spacers 270, as described above.

Fasteners configured to fasten v-shaped stem 50 to fork top 205 mayadditionally be configured to secure one or more stem spacers 270between upper surface 207 and lower surface 103. For example, one ormore screws and/or bolts may extend through upper surface 207, one ormore stem spacers 270, and lower surface 103. Stem spacers 270 areconfigured to receive cables 115 routed from junction portion 54 intohead tube portion 150. For example, stem spacers 270 may include one ormore apertures configured to receive cables 115.

In some examples, stem spacers 270 each comprise two or more componentsconfigured to fit together about an aperture configured to receivecables 115. In other words, stem spacer 270 is configured to beassembled around cables 115, so that the stem spacer can be installedwithout removing cables 115 from their ordinary positions. The two ormore components of stem spacer 270 may be fitted together by clips,screws, clamps, complementary recesses and projections, and/or any othersuitable attachment mechanism.

Stem spacers 270 allow adjustment of a vertical position of base bar 45relative to fork top 205. Inserting stem spacers 270 between fork top205 and v-shaped stem 50 increases a vertical distance between base bar45 and fork assembly 200, and may additionally or alternatively changean angle between the base bar and the fork assembly. In some examples,stem spacers 270 include a set of at least three spacers, each of thethree spacers having a different thickness. By selectively insertingdifferent combinations of spacers 270 of varying thicknesses, a user ofbicycle 30 may choose between a plurality of different verticaldistances between base bar 45 and fork top 205. In this way, a positionof base bar 45 may be conveniently adjusted to suit different sizesand/or preferences of one or more bicycle riders.

Base bar spacers 280 may be selectively disposed between spaced-apartlocations 80 of base bar 45 and corresponding distal ends 56 of stemmembers 52 of v-shaped stem 50 to selectively adjust a vertical distanceand/or an angle between base bar 45 and v-shaped stem 50. Typically,base bar spacers 280 are configured to be secured between base bar 45and stem members 52 by nut plates 70. For example, fasteners 90extending through fastener apertures 92 within distal ends 56 and intobores 75 of nut-plate projections 72 may also pass through base barspacers 280. A plurality of different fasteners 90 may be provided toallow for different numbers or different thicknesses of base bar spacers280. In some examples, base bar spacers 280 include, for each of the twostem members 52, at least three base bar spacers having differentthicknesses.

Base bar spacers 280 may be configured to allow cables 115 to pass fromgrooves 100 into stem members 52. For example, the base bar spacers 280may include apertures and/or grooves configured to receive cables 115.Base bar spacers 280 may each comprise two or more components configuredto fit together about cables 115, as described above with reference tostem spacers 270.

Base bar spacers 280 allow adjustment of a vertical position of base bar45 relative to v-shaped stem 50. As with stem spacers 270, differentselections of one or more base bar spacers 280 may allow bicycle 30 tobe adapted to suit different rider sizes or rider preferences. Dependingon the shapes of base bar spacers 280, stem spacers 270, fork assembly200, v-shaped stem 50, base bar 45, and/or other components of bicycle30, insertion of one or more base bar spacers and/or stem spacers mayalso adjust horizontal distances between the base bar, the v-shapedstem, and/or the fork assembly. Accordingly, these horizontal distancesmay be selectively adjusted by inserting a selected combination of basebar spacers 280 and/or stem spacers 270.

In some examples, stem spacers 270 and/or base bar spacers 280 areconfigured to adjust an angle between base bar 45 and v-shaped stem 50and/or an angle between the v-shaped stem and fork top 205. For example,the spacers may be wedge-shaped. Spacers configured for angularadjustment (e.g., for tilting base bar 45) may allow for furtherfine-tuning rider position on bicycle 30. A plurality of stem spacers270 and/or base bar spacers 280 each configured for a different amountof angular adjustment may be provided. Spacers configured for angularadjustment may be used in combination with spacers configured fordistance adjustment to achieve a desired bicycle geometry.

E. Illustrative Aerobar Extension Assembly

As shown in FIGS. 18-20 , this section describes an illustrative aerobarextension assembly 300. Aerobar extension assembly 300 is an example ofan accessory attachable to base bar 45, as described previously.

FIG. 18 depicts aerobar extension assembly 300 attached to base bar 45via one of nut plate apertures 60 (not visible) on one side of the basebar. Typically, a second aerobar extension assembly 300 is attached tobase bar 45 via the other nut plate aperture 60, but the second(left-hand) aerobar extension assembly is omitted from FIG. 18 forclarity. Alternatively, a single extension assembly or other accessorymay attach to base bar 45 via both nut plate apertures 60.

As shown in FIG. 18 , aerobar extension assembly 300 includes anelongate extension portion 305, an armrest pad 310, and an engagementportion 315 (also called an attachment portion) configured to attach theextension portion and the pad to base bar 45. Engagement portion 315also secures one of the stem members 52 to base bar 45, as describedfurther below.

A rider of bicycle 30 may grip extension portion 305 in one hand andrest a forearm on pad 310. Using aerobar extension assembly 300 in thisway may help the rider to assume an aerodynamic position on the bicycle.In the example depicted in FIG. 18 , extension portion 305 issubstantially straight, but in other examples, the extension portion maybe curved or angled. For example, extension portion 305 may be J-shaped,S-shaped, or shaped in any other suitable geometry.

In some examples, extension portion 305 is connected to engagementportion 315 by a sleeve 317 attached to the engagement portion andconfigured to receive the extension portion. Sleeve 317 may beconfigured to selectively receive any one of a plurality ofinterchangeable extension portions 305, or a single extension portionwhich can slide within sleeve 317 to adjust the overall length of theaerobar extension.

Engagement portion 315 is configured to secure aerobar extensionassembly 300 to base bar 45 while also securing one of the stem members52 to the base bar. Accordingly, in some examples, engagement portion315 includes features similar to nut plate 70 (see FIGS. 3-5 ).

FIGS. 19-20 depict an illustrative embodiment of engagement portion 315having engagement projections 322. Like nut-plate projections 72 (seeFIGS. 3-5 ), engagement projections 322 extend through complementaryopenings in nut-plate apertures 60 in top portion 65 of base bar 45toward bottom-surface apertures 84 in bottom surface 82 of the base bar.FIG. 20 depicts engagement projections 322 extending through bottomsurface 82 at depression 83. Engagement projections 322 may each have arespective bore 325 configured to receive a fastener, such as fastener90. The fasteners retain v-shaped stem 50 against bottom surface 82 bypassing through fastener apertures 92 within distal ends 56 of stemmembers 52, and being securely received in bores 325 of engagementprojections 322. In this way, engagement portion 315 secures v-shapedstem 50 and aerobar extension assembly 300 against base bar 45.

In the example depicted in FIGS. 19-20 , engagement portion 315 includestwo engagement projections 322. In other examples, there may be morethan two or fewer than two engagement projections 322. In some examples,the number of engagement projections 322 is the same as the number ofcomplementary openings in nut-plate apertures 60 corresponding to theassociated spaced-apart location 80.

In the example depicted in FIGS. 19-20 , nut plate 70 is absent frombase bar 45 while aerobar extension assembly 300 is attached to the basebar. Alternatively, or additionally, nut plate 70 may be used to attachaerobar extension assembly 300 to base bar 45. For example, engagementportion 315 may include apertures configured to align with nut-plateapertures 60, and nut-plate projections 72 may extend through theapertures of the engagement portion into nut-plate apertures 60 andbottom-surface apertures 84. Fasteners 90 may then fasten v-shaped stem50 and aerobar extension assembly 300 to base bar 45. In other words,nut-plate projections 72 rather than engagement projections 322 mayattach aerobar extension assembly 300 and v-shaped stem 50 to base bar45. Engagement projections 322 may be omitted in these examples.

F. Illustrative Combinations and Additional Examples

This section describes additional aspects and features of handlebarassemblies having v-shaped stems, presented without limitation as aseries of paragraphs, some or all of which may be alphanumericallydesignated for clarity and efficiency. Each of these paragraphs can becombined with one or more other paragraphs, and/or with disclosure fromelsewhere in this application, in any suitable manner. Some of theparagraphs below expressly refer to and further limit other paragraphs,providing without limitation examples of some of the suitablecombinations.

A0. A bicycle handlebar assembly, comprising a base bar; and a v-shapedstem, selectively attachable to the base bar, including a pair of stemmembers diverging from a junction portion; each stem member having anaperture near a distal end configured to receive one or more of thecontrol cables from a bottom surface of the base bar into a hollowinterior of the corresponding stem member; and the junction portion ofthe stem having an aperture for routing the control cables from the stemmembers into a head tube portion of a bicycle frame.

A1. The bicycle handlebar assembly of paragraph A0, wherein the base barincludes a pair of nut plate apertures disposed along a top portion ofthe base bar, each nut plate aperture configured to receive either aretaining nut plate for securing one of the stem members to the basebar, or an attachment portion of an aerobar extension configured tosecure the aerobar extension to the base bar while also securing one ofthe stem members to the base bar.

A2. The bicycle handlebar assembly of paragraph A0, further comprisingmeans for securing the stem to the base bar.

A3. The bicycle handlebar assembly of paragraph A2, further comprisingmeans for attaching aerodynamic bar extensions to a top portion of thebase bar.

A4. The bicycle handlebar assembly of any one of paragraphs A0 throughA3, further comprising a fork assembly configured to fit partiallywithin the head tube portion of the bicycle frame, the fork assemblyincluding (i) a top aperture configured to receive the control cablesfrom the stem members, (ii) a load-bearing member disposed at a frontsurface of the fork assembly, (iii) a preload tensioning rod disposedalong an axis of rotation of the fork assembly, and (iv) a hollowportion disposed around the tensioning rod and configured to accommodatethe control cables as they pass through the head tube portion.

A5. The bicycle handlebar assembly of paragraph A4, further comprisingat least one spacer configured to fit between a lower surface of thejunction portion of the stem and an upper surface of the fork assembly,wherein the at least one spacer increases a vertical distance betweenthe base bar and the fork assembly.

A6. The bicycle handlebar assembly of any one of paragraphs A4 throughA5, further comprising a bicycle frame including a head tube having afront surface with a shape complementary to a shape of a rear surface ofthe load bearing member of the fork assembly, and an aperture in thehead tube configured to receive at least some of the control cables fromthe fork assembly into an interior portion of the bicycle frame.

B0. A bicycle handlebar assembly, comprising a base bar including meansfor routing bicycle control cables from shifter assemblies of thebicycle disposed at lateral edge portions of the base bar to a pair ofspaced apart locations symmetrically disposed along a bottom surface ofthe base bar; and a stem including a pair of diverging stem membersextending from a junction portion in a v-shaped configuration; whereinthe stem is selectively attachable to the base bar, wherein each stemmember has an aperture at its distal end which is configured to receiveat least one of the control cables from a complementary one of thespaced apart locations into a hollow interior of the stem member, andwherein the junction portion of the stem has an aperture for routing thecontrol cables from the stem members into a head tube portion of abicycle frame.

B1. The bicycle handlebar assembly of paragraph B0, further comprising apair of nut plate apertures symmetrically disposed along a top surfaceof the base bar, wherein each nut plate aperture is configured toreceive a nut plate that engages a corresponding one of the stem membersthrough the base bar and thereby securely fastens the corresponding stemmember to the base bar.

B2. The bicycle handlebar assembly of paragraph B1, wherein each nutplate aperture is configured to receive an engagement portion of anaerobar extension assembly which includes (i) means for attaching theaerobar extension assembly to the base bar and (ii) means for securelyfastening the corresponding stem member to the base bar.

B3. The bicycle handlebar assembly of any one of paragraphs B0 throughB2, further comprising a fork assembly including (i) a top apertureconfigured to receive the control cables from the stem members, (ii) aload-bearing member disposed at a front surface of the fork assembly,and (iii) a hollow portion disposed adjacent to the load-bearing memberand configured to accommodate the control cables as they pass throughthe fork assembly.

B4. The bicycle handlebar assembly of paragraph B3, further comprisingat least one spacer configured to be removably disposed between a lowersurface of the stem and an upper surface of the fork assembly to adjusta vertical distance between the base bar and the fork assembly.

B5. The bicycle handlebar assembly of paragraph B4, wherein the at leastone spacer includes a set of at least three spacers of varyingthicknesses.

C0. A bicycle handlebar assembly, comprising a base bar includinggrooves symmetrically disposed along a bottom surface of the base bar,each groove shaped to accommodate control cables of a bicycle, and eachgroove extending to a depression formed in the bottom surface of thebase bar; a stem, selectively removable from the base bar, including apair of diverging stem members extending from a junction portion in av-shaped configuration, each stem member including a distal endconfigured to mate and align with one of the depressions formed in thebottom surface of the base bar, and the distal end of each stem memberfurther including an aperture configured to receive control cables fromone of the grooves of the base bar into a hollow interior portion of thecorresponding stem member; and a pair of nut plate receiving aperturessymmetrically disposed along a top surface of the base bar and eachconfigured to receive either a retaining nut plate for securing one ofthe stem members to the base bar, or an attachment portion of an aerobarextension configured to secure the aerobar extension to the top surfaceof the base bar while also securing one of the stem members to the basebar.

C1. The bicycle handlebar assembly of paragraph C0, further comprising abayonet-style fork assembly, wherein the junction portion of the stemincludes an aperture configured to mate and align with an aperture ofthe fork assembly.

C2. The bicycle handlebar assembly of paragraph C1, wherein the forkassembly includes a fork top configured to mate and align with thejunction portion of the stem, a front load-bearing portion, a centraltensioning rod, a space around the tensioning rod to accommodate passageof control cables, and a pair of fork blades, and wherein theload-bearing portion extends between the fork top and the fork blades.

C3. The bicycle handlebar assembly of paragraph C2, wherein the frontload-bearing portion of the fork assembly is configured to rotate withrotation of the base bar, external to any tubes of the bicycle.

C4. The bicycle handlebar assembly of any one of paragraphs C2 throughC3, further comprising a plurality of spacers of varying thicknesses,each configured to mate and align with the junction portion of the stemand with the fork top, and to fit between the junction portion of thestem and the fork top to allow adjustment of a vertical position of thebase bar relative to the fork top.

D0. A bicycle handlebar assembly, comprising a base bar; a stem,selectively removable from the base bar, including a pair of hollowdiverging stem members extending from a junction portion in a v-shapedconfiguration; means for routing control cables of a bicycle from thebase bar and into the stem; and means for securing the stem to a bottomsurface of the base bar; and means for selectively securing aerobarextensions to a top surface of the base bar.

D1. The bicycle handlebar assembly of paragraph D0, further comprisingmeans for attaching the stem to a fork assembly; and means forincreasing vertical separation between the base bar and the forkassembly.

Advantages, Features, and Benefits

The different embodiments and examples of the bicycle handlebar assemblydescribed herein provide several advantages over assemblies. Forexample, illustrative embodiments and examples described herein allow ahandlebar assembly having an aerodynamic stem.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow a handlebar assembly having increasedstiffness and more precise handling.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow bicycle cables to be routed from controlassemblies into a bicycle frame such that the cables are curved alongwide angles with gradual changes in direction, avoiding sharp angles andrapid changes in direction. This routing allows lower friction andbetter performance for mechanical cables.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow bicycle cables to be routed through anupper bearing race of the fork assembly, which may reduce the travelinduced in the cables by rotation of the base bar (e.g., when thebicycle is steered).

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow for a vertical distance and/or an anglebetween the base bar and the fork assembly to be easily adjusted to suitthe requirements and preferences of different riders and/or differentriding conditions.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow for a stem to be fastened to a base barof a handlebar assembly by an attachment portion of an attached aerobarextension assembly. This allows a lighter overall weight compared tosystems in which two or more separate attachment mechanisms are used tofasten the aerobar extension and the stem to the handlebar.

No known system or device can perform these functions. However, not allembodiments and examples described herein provide the same advantages orthe same degree of advantage.

CONCLUSION

The disclosure set forth above may encompass multiple distinct exampleswith independent utility. Although each of these has been disclosed inits preferred form(s), the specific embodiments thereof as disclosed andillustrated herein are not to be considered in a limiting sense, becausenumerous variations are possible. To the extent that section headingsare used within this disclosure, such headings are for organizationalpurposes only. The subject matter of the disclosure includes all noveland nonobvious combinations and subcombinations of the various elements,features, functions, and/or properties disclosed herein. The followingclaims particularly point out certain combinations and subcombinationsregarded as novel and nonobvious. Other combinations and subcombinationsof features, functions, elements, and/or properties may be claimed inapplications claiming priority from this or a related application. Suchclaims, whether broader, narrower, equal, or different in scope to theoriginal claims, also are regarded as included within the subject matterof the present disclosure.

What is claimed is:
 1. A bicycle handlebar assembly, comprising: a basebar; and a v-shaped stem, selectively attachable to the base bar,including a pair of stem members diverging from a junction portion; eachstem member having an aperture near a distal end configured to receiveone or more control cables from a bottom surface of the base bar into ahollow interior of the corresponding stem member; and the junctionportion of the stem having an aperture for routing the control cablesfrom the stem members into a head tube portion of a bicycle frame;wherein the base bar includes a pair of attachment apertures disposedalong a top portion of the base bar, each attachment aperture configuredto receive an attachment portion of an aerobar extension configured tosecure the aerobar extension to the base bar while also securing one ofthe stem members to the base bar.
 2. The bicycle handlebar assembly ofclaim 1, further comprising means for securing the stem to the base bar.3. The bicycle handlebar assembly of claim 2, further comprising meansfor attaching aerodynamic bar extensions to a top portion of the basebar.
 4. The bicycle handlebar assembly of claim 1, further comprising afork assembly configured to fit partially within the head tube portionof the bicycle frame, the fork assembly including (i) a top apertureconfigured to receive the control cables from the stem members, (ii) aload-bearing member disposed at a front surface of the fork assembly,(iii) a preload tensioning rod disposed along an axis of rotation of thefork assembly, and (iv) a hollow portion disposed around the tensioningrod and configured to accommodate the control cables as they passthrough the head tube portion.
 5. The bicycle handlebar assembly ofclaim 4, further comprising at least one spacer configured to fitbetween a lower surface of the junction portion of the stem and an uppersurface of the fork assembly, wherein the at least one spacer increasesa vertical distance between the base bar and the fork assembly.
 6. Thebicycle handlebar assembly of claim 4, further comprising a bicycleframe including a head tube having a front surface with a shapecomplementary to a shape of a rear surface of the load-bearing member ofthe fork assembly, and an aperture in the head tube configured toreceive at least some of the control cables from the fork assembly intoan interior portion of the bicycle frame.
 7. A bicycle handlebarassembly, comprising: a base bar including means for routing bicyclecontrol cables from shifter assemblies of the bicycle disposed atlateral edge portions of the base bar to a pair of spaced apartlocations symmetrically disposed along a bottom surface of the base bar;a stem selectively attachable to the base bar, the stem including a pairof diverging stem members extending from a junction portion in av-shaped configuration, wherein a distal end of each stem member has anaperture at its distal end which is configured to receive at least oneof the control cables from a complementary one of the spaced apartlocations into a hollow interior of the stem member, and wherein thejunction portion of the stem has an aperture for routing the controlcables from the stem members into a head tube portion of a bicycleframe; and a pair of apertures symmetrically disposed along a topsurface of the base bar, wherein each aperture is configured to receivean engagement portion of an aerobar extension assembly which includes(i) means for attaching the aerobar extension assembly to the base barand (ii) means for securely fastening the corresponding stem member tothe base bar.
 8. The bicycle handlebar assembly of claim 7, furthercomprising a fork assembly including (i) a top aperture configured toreceive the control cables from the stem members, (ii) a load-bearingmember disposed at a front surface of the fork assembly, and (iii) ahollow portion disposed adjacent to the load-bearing member andconfigured to accommodate the control cables as they pass through thefork assembly.
 9. The bicycle handlebar assembly of claim 8, furthercomprising at least one spacer configured to be removably disposedbetween a lower surface of the stem and an upper surface of the forkassembly to adjust a vertical distance between the base bar and the forkassembly.
 10. The bicycle handlebar assembly of claim 9, wherein the atleast one spacer includes a set of at least three spacers of varyingthicknesses.
 11. A bicycle handlebar assembly, comprising: a base barincluding grooves symmetrically disposed along a bottom surface of thebase bar, each groove shaped to accommodate control cables of a bicycle,and each groove extending to a depression formed in the bottom surfaceof the base bar; a stem, selectively removable from the base bar,including a pair of diverging stem members extending from a junctionportion in a v-shaped configuration, each stem member including a distalend configured to mate and align with one of the depressions formed inthe bottom surface of the base bar, and the distal end of each stemmember further including an aperture configured to receive controlcables from one of the grooves of the base bar into a hollow interiorportion of the corresponding stem member; and a pair of aperturessymmetrically disposed along a top surface of the base bar and eachconfigured to receive an attachment portion of an aerobar extensionconfigured to secure the aerobar extension to the top surface of thebase bar while also securing one of the stem members to the base bar.12. The bicycle handlebar assembly of claim 11, further comprising abayonet-style fork assembly, wherein the junction portion of the stemincludes an aperture configured to mate and align with an aperture ofthe fork assembly.
 13. The bicycle handlebar assembly of claim 12,wherein the fork assembly includes a fork top configured to mate andalign with the junction portion of the stem, a front load-bearingportion, a central tensioning rod, a space around the tensioning rod toaccommodate passage of control cables, and a pair of fork blades, andwherein the load-bearing portion extends between the fork top and thefork blades.
 14. The bicycle handlebar assembly of claim 13, wherein thefront load-bearing portion of the fork assembly is configured to rotatewith rotation of the base bar, external to any tubes of the bicycle. 15.The bicycle handlebar assembly of claim 14, further comprising aplurality of spacers of varying thicknesses, each configured to mate andalign with the junction portion of the stem and with the fork top, andto fit between the junction portion of the stem and the fork top toallow adjustment of a vertical position of the base bar relative to thefork top.
 16. A bicycle handlebar assembly, comprising: a base bar; astem, selectively removable from the base bar, including a pair ofhollow diverging stem members extending from a junction portion in av-shaped configuration; means for routing control cables of a bicyclefrom the base bar and into the stem; and a pair of apertures disposedalong a top portion of the base bar, each aperture configured to receivean attachment portion of an aerobar extension configured to secure theaerobar extension to the base bar while also securing one of the stemmembers to the base bar.
 17. The bicycle handlebar assembly of claim 16,further comprising: means for attaching the stem to a fork assembly; andmeans for increasing vertical separation between the base bar and thefork assembly.